This invention relates to flexible sound insulating units, and to sound barriers utilizing such units.
Various measures have heretofore been taken to control noise, such as by the reduction in the generation of noise at its source, enclosing the sound source and insulating against airborne noise.
Reduction in the generation of sound, as from machines or the like, has been in progress by use of improved materials and by modifying the construction of the machines. On the other hand, heavy and hard materials such as steel, concrete and the like have been commonly used as permanent sound insulators. However, these materials are not suitable for temporary sound insulation, i.e., the control of noise for construction sites, machines used for a short period, and the like. Such hard and heavy materials are not easily fabricated into soundproof structures of complicated shape. For example, sound insulating panels consisting of wire nets and sound insulating plates have been used at construction sites by placing them on scaffolding or metal frames. The drawbacks of such panels are that noise leaks occur through gaps that exist between the panels. Also, they are costly to form, can easily be broken and are difficult to use.
It is an object of the present invention to provide sound insulating units and barriers which are easy to use and possess excellent insulating capabilities.
In accordance with the present invention, the sound insulating unit includes a flexible sheet having a surface density of at least 2.0 Kg/cm.sup.2 which is capable of overlapping with similar flexible sheets, at least in the area where the sheet is connected to a supporting means. This invention also provides a sound barrier which is formed with the aforementioned sound insulating sheets.